ORA-01017 when changing expired password on oracle 11G

We have implemented password expiry and complexity rules on all our
databases and one recent one is giving us some headache by giving us
ORA-01017 when we connect remotely to change it
We already set sec_case_sensitive_logon to false to accomodate 10G clients
but even from my desktop I get this error and I have 11.2.0.3 client.
If I run the same on the server it works fine.

I am sure it is something minor, but I can't see it

There is no sqlnet.ora on the server
I do know that the Linux team have made modifications to secure the server
more than the default but am not aware of the full details yet, but that
may be my next port of call.

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